ML20212P378
| ML20212P378 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 02/06/1987 |
| From: | FLORIDA POWER CORP. |
| To: | |
| Shared Package | |
| ML20212N983 | List:
|
| References | |
| NUDOCS 8703160090 | |
| Download: ML20212P378 (64) | |
Text
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SYSTEM DESCRIPTION 15-1121209-05 FOR i
EMERGENCY FEEDWATER SYSTEM FOR FLORIDA POWER CORPORATION CRYSTAL RIVIP UNIT 3 i
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B703160090 870305 2 DR ADOCK 050
SIGN OFF SHEET DOCUMENT NUMBER REVISION DESCRIPTION 15-1121209 5 This revision incorporates Crysta; River-3 comments
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TABLE OF CONTENTS SECTION TITLE PAGE 1.0 SCOPE 1 2.0 SYSTEM REQUIREMENTS 1 i
2.1 NSS Interface Requirements 1 2.1.1 Maximum Emergency Feedwater Flow 1 2.1.2 Minimum Available Emergency Feedwater Flow 1 2.1.3 Maximum Automatic Initiation Time 1 2.1.4 Initiation and Control Requirements 2 2.1.4.1 General Requirements 2 2.1.4.2 Actuation Requirements 3 2.1.4.3 Level Requirements 4 2.1.4.4 Level Rate Requirements 4 2.1.5 Steamline Breah/Feedwater Line Break 4 2.1.6 Steam Generator Overfill 5 2.2 Fluid System Requirements 5 2.2.1 Branch Technical Position ASB10-1 5 2.2.2 Water Sources 6 2.2.3 EFW Pump Protection 6 2.2.4 EFW Support Systems 7 2.2.5 Cross Connects 7 2.2.6 Alarms 7 2.2.7 Indication -
7 2.2.8 Physical Separation S 2.2.9 Fluid Flow Instabilities 8 Page ii
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2.2.10 Operational Testing 8 2.2.11 Water Chemistry 8 2.2.12 Power 8 2.2.13 Interface with Valve and Pump Controllers 9 2.3 Codes and Standards 9 TABLE 2-1 OTSG EMERGENCY FEEDWATER CHEMISTRY 12 REQUIREMENTS 3.0 DESIGN DESCRIPTION 13 3.1 Summary Description 13 3.2 Fluid Systems Design 13 3.2.1 Suction 13 3.2.2 Pumps and Discharge Cross-Connect 14 3.2.3 Emergency Feedwater Flow Control Valves 14
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3.2.4 Steam Generator EFW Isolation Valves 14 3.2.5 Recirculation and Test Lines 14 3.2.6 Steam Supply for the EFW System Turbine 15 3.3 Supporting Systems 15 3.3.1 Power 15 3.4 Instrumentation Description 16 3.4.1 Input logic 17 3.4.2 Initiate Logic 17 l 3.4.3 Trip Logic 18 3.4.4 Vector Logic 2C 3.4.5 Control Logic 21 3.4.6 EFIC Trip Testing 23 3.4.7 EFIC Signal Application 24 l
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3.4.8 OTSG Level Sensing 25 4.0 SYSTEM LIMITS, PRECAUTIONS AND SETPOINTS 26 4.1 Limits and Precautions 26 4.1.1 EFW Flow Limits 26 4.1.2 EFW Pump Suction Pressure 26 4.1.3 System Limits (Design) 26 4.1.4 Minimum Pump Recirculation 26 4.2 Setpoints 26 4.2.1 Low SG Level EFW Initiate Setpoint 27 4.2.2 EFW Control Level (3 Foot Level) Setpoint 27 4.2.3 Natural Circulation Control Level 27 (20 Foot Level) Setpoint 4.2.4 Steam Generator Overfill Setpoint 27 4.2.5 ECCS Fill Limit Setpoint (31.5 Feet Level) 27 4.2.6 Low Steam Generator Pressure Setpoint 28 4.2.7 Steam Generator Differential Pressure 28 Setpoint 4.2.8 Atmospheric Dump Valve Operating Setpoint 28 5.0 OPERATION 29 5.1 Heatup from Cold Shutdown to Hot Standby 29 5.2 Hot Standby to Full Power 29 l
5.3 Cooldown from Hot Stanby to Cold Shutdown 29
' 5. 4 Wet Layup 30 6.0 CASUALTY EVENTS AND RECOVERY PROCEDURES 31 6.1 Casualty Events 31 Page iv
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d 6.2 Design Features to Mitigate Effects of 31 Casualty Events 6.2.1 Loss of Main Feedwater (LMFW) 31 6.2.2 Loss of Main Feedwater with Loss of Offsite 31 AC Power 6.2.3 Loss of Main Feedwater with Loss of Onsite 32 and Offsite AC Power 6.2.4 Plant Cooldown 32 6.2.5 Turbine Trip With and Without Bypass 32 6.2.6 Main Steamline Isolation Valve Closure 32 6.2.7 Main Feedline Break 33 6.2.8 Main Steamline Break 33 6.2.9 Small Break LOCA 33 6.2.10 OTSG Overfill 34 7.0 TESTING AND MAINTENANCE 35 7.1 Periodic Testing of the Fluid System 35 7.2 Periodic Testing of the EFIC 35 FIGURE 3.3-1 SIMPLIFIED POWER SOURCE DIAGRAM 37 FIGURE 3.3-2 SIMPLIFIED POWER SOURCE DIAGRAM- 38 DC LOADS FIGURE 3.3-3 SIMPLIFIED POWER SOURCE DIAGRAM- 39 AC VALVES TABLE 4.2-1 EFW SYSTEM SETPOINTS 40 APPENDIX A TABUhTION OF DRAWING NUMBERS VS. A-1 FIGURE NUMBERS FOR CRYSTAL RIVER-3 EFW SYSTEM APPENDIX B INSTRUMENTATION REQUIREMENTS S-1 APPENDIX C EFW SYSTEM CONTROL VALVE REQUIREMENTS C-1 Page v
APPENDIX D BALANCE OF PLANT CRITERIA FOR EFIC D-1 1.O PHYSICAL SEPARATION D-1 2.0 ELECTRICAL ISOLATION NON 1E D-2 3.0 GROUNDING D-2 4.0 ELECTRICAL POWER REQUIREMENTS D-4 5.0 ELECTRICAL CURRENT RATINGS D-4 6.O CABLE COUNT D-4 FIGURE 1 EFIC CHANNEL A SEPARATION D-E FIGURE 2 EFIC CHANNEL B SEPARATION D-9 FIGURE 3 EFIC CHANNEL C SEPARATION D-lC FIGURE 4 EFIC CHANNEL D SEPARATION D-11 Page vi
1.0 SCOPE This document contains the system description for emergency feed water (EFW). The requirements for this system come from four sources - first, the functional requirements needed to properly interface the EFW system with the nuclear steam supply system (NSSS);
second, NUREG-0578, Short Term Lessons Learned Repert:
third, Draft NUREG-0667, Transient Response of B&W Designed Reactors ; fourth, NUREG-0737, Clarificatier of TMI Action Plan Requirements. This document contains the criteria necessary to upgrade the EFW system to comply with the Standard Review Plan Sectier 10.4.9, Branch Technical Position ASBlO-1 and other standards generally applied to new designs. In implementing these requirements, some exceptions may be taken where the improvement in system reliability is se small that the required modification is not justified for an operating plant. Note that "feedwater", as used in this document, refers to EFW unless otherwise stated.
2.0 SYSTEM REOUIREMENTS The EFW system requirements are listed below.
2.1 NSS Interface Recuirements 2.1.1 Maximum Emercencv Feedwater Flow The maximum allowable EFW flow is 1830 gpm per stear generator (SG). This limit shall not be exceeded at any steam pressure.
2.1.2 Minimum Available Emercencv Feedwater Flow The EFW system shall be sized so that a minimum of 4 gpm (total) can be delivered to either one or both SGs at a SG pressure of 1050 psig. This flow shall be available for all accident conditions considered in the design basis for the plant even with a sincie active failure in the system.
2.1.3 Maximum Automatic Initiation Time The system shall be designed so that the minimur EFW flow is established within 50 seconds after an initiation signal is reached. This initiation time is j based on the requirement to:
l A. Maintain continuity in the reactor coolant syster l
l (RCS) flow in the transition from forced to l Page 1 1
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natural circulation when the RC pumps (RCPs) are tripped.
B. Provide margin to prevent overpressurization of the RCS following a loss of main FW event and reactor trip.
And the desirability of:
C. Reducing the probability of boil off of the entire inventory of water immediately following a less cf main FW occurrence.
NOTE: The 50 second worst case delay includes instrumentation time delay, diesel startup, diesel sequencing, pump acceleration time and valve stroke time. Without ESAS actuation, diesel startup and sequencing, normal delay is mostly pump acceleration since syster valves are normally open.
2.1.4 Initiation and Control Recuirements 2.1.4.1 General Recuirements The requirements to which the EFW control system shall be designed are:
A. The system shall provide automatic actuation of EFW for the conditions specified in Section 2.1.4.2. The capability for bypassing certain initiations shall be provided for unit startup or shutdown in accordance with the IEEE-279 provisions for shutdown bypasses.
I B. The system shall be designed to minimize l overcooling following a loss of main FW event.
This feature of the system is not required :: rest i the single failure criterion.
I C. The system, including control valve positioners, sensors, control and actuation signals and their auxiliary supporting systems, shall be designed as a safety grade (IE) system to the extent possi le.
As such, it shall be independent of the ICS, NN:,
and other non-safety systems.
l l D. Redundancy and testability shall be provided ::
l enhance the reliability demanded of a safety grade l system.
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E. A single failure shall neither prevent actuation of EFW, when required, nor spuriously actuate the system. This criterion shall apply to the EFW system and its auxiliary supporting features. In addition to this single failure, all failures which can be predicted as a condition or a result of the initiating event requiring EFW shall be considered.
F. Indication of EFW status, flowrate and OTSG level shall be available to the operator.
G. The capability for a manual override of the automatic functioning of the system shall be provided. This condition shall be annunciated in the control room.
H. The capability for manual initiation of EFW shall be provided.
I. The capability for manual initiation and control shall be provided in the main control room. The capability of control from a remote shutdown panel shall be provided.
J. The system shall be designed to prevent or minimize cycling of f the EFW control valve during normal plant operation when the EFW syster is not in operation.
K. The system shall provide the capability to control the atmospheric dump valves to a single predetermined setpoint and, in addition, shall have manual override capability.
2.1.4.2 Actuation Recuirements EFW shall be automatically initiated after the occurrence of any of the following conditions:
o Loss of all main FW as a minimum, as indicated by the loss of both main FW pumps.
o Low level in either SG.
o Loss of 4 RCPs.
o Low pressure in either SG.
o ESFAS HP Actuation (High RB Pressure or Low R.C.
pressure)
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2.1.4.3 Level
- Recuirements Three adjustable level setpoints are required.
A. Following EFW actuation,.the level setpoint shall be automatically selected to approximately 3 feet if one or more RCPs are running.
B. Following EFW actuation, the level setpoint shall be automatically selected to approximately 20 fee if all 4 RCPs are tripped.
C. provision for manual selection of a high level setpoint of approximately 31.5 feet shall be provided. This setpoint will be selected by the operator in accordance with operating guidelines.
- For the purpose of EFW design, " LEVEL" refers to the equivalent height of a saturated liquid column (1065 psia) referenced from the top of the lower tube sheet.
2.1.4.4 Level Rate Recuirements A level rate of 2 inches / minute to 8 inches / minute shall be provided. This fill rate shall be varied as a function of steam generator pressure in the range of 800 to 1050 psig for the transient conditions which require EFW.
The level rate limit shall be adjustable under administrative control.
2.1.5 Steamline Break /Feedwater Line Break A steamline break or FW line break that depressurizes a SG shall cause the isolation of the main steamlines and
the SG does not isolate the break, EFW shall be provided only to the intact SG. No single active failure in the system shall prevent EFW from being supplied to the intact SG nor allow EFW to be supplied to the broken SG.
To meet these requirements the following design shall be implemented:
- a. Isolation - Low steam pressure (below approximately 600 psig) in either SG will isolate the main steamlines and main FW line to the affected SG.
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B. SG Selection -
o If both SGs are above 600 psig, supply EFW to both SGs.
i o If one SG is below 600 psig, supply EFW to l the other SG.
o If both SGs are below 600 psig but the pressure difference between the two SGs exceeds a fixed setpoint (approximately 100 psig) supply EFW only to the SG with the higher pressure.
o If both SGs are below 600 psig and the pressure difference is less than the fixed setpoint, supply EFW to both SGs.
2.1.6 Steam Generator Overfill Provisions shall be made in the design to terminate an EFW overfill condition. Provisions shall also be made to manually bypass the EFW overfill setpoint following a LOCA to permit establishing an OTSG level which will support steam condensation natural circulation in the RCS.
2.2 Fluid System Recuirements 2.2.1 Branch Technical Position ASBlo-1 BTP ASBlO-1 places the following requirements on the EFW system:
A. The EFW system shall consist of at least two full capacity independent systems that include diverse power sources. ,
B. Other powered components of the emergency FW
, system shall also use the concept of separate and i multiple sources of motive energy. An example of the required diversity would be two separate EFW trains, each capable of removing the heat load cf the reactor system, having one separate train powered from either of two AC sources and the other train wholly powered by steam and DC electric power.
C. The piping arrangement, both intake and discharge, for each train shall be designed to permit the pumps to supply EFW to any combination of SGs.
This arrangement shall take into account pipe Page 5
failure, active component failure, power supply failure or control system failure that could prevent system function. One arrangement that would be acceptable is crossover piping containing valves that can be operated by remote manual control from the control room, using the power diversity principle for the valve operators and actuation systems.
D. The EFW system shall be designed with suitable redundancy to offset the consequences of any single active component failure; however, each train need not contain redundant active components.
E. When considering a high energy line break, the system shall be so arranged as to assure the capability to supply necessary EFW to the SG despite the postulated rupture of any high energy section of the system, assuming a concurrent single active failure.
NOTE: If the EFW system is not used (and therefore not pressurized) during startup, hot standby and shutdown conditions, then a high energy line break in the EFW system only needs to be considered between the SG and the first check valve upstream of the SG.
2.2.2 Water Sources Seismic Category I water sources shall be provided cf sufficient volume to remove decay heat for four hours and to subsequently cooldown the plant to the decay heat removal (DHR) system pressure.
2.2.3 EFW Pump Protection The system design shall protect the EFW pump fror runout and cavitation due to high energy line breaks or single failures in the system. The main concern is following a Steam Line Break (SLB). The existing SLE analysis depicts the plant response for a given set of assumptions and single failures; however, these assumptions and postulated failures were not specifically formulated to yield the lowest stear generator pressure condition. Therefore the EFW syster will be required to operate against a steam generatcr pressure of zero to ensure protection against pump runout and cavitation following a SLB. Any automatic pump trip failure, designed to protect the pump, must Page 6
not override automatic initiation and must be designed as Class lE.
2.2.4 EFW Succort Systems The requirements for diverse power sources and operation with a single failure also apply to the EFW support systems. These systems include:
o Electrical power to support systems o Nuclear Services Closed Cycle Cooling o Main Steam o Condensate 2.2.5 Cross Connects The EFW system shall be designed to allow either pump to feed either steam generator. Cross connects provided for this purpose shall include normally cpen remotely operated isolation valves.
2.2.6 Alarms As a minimum, the following alarms should be provided from the plant control equipment:
o High SG level. (For SG A and SG B) o Low SG level. (For SG A and SG B) o Low source water level.
o Low EFW pump discharge pressure. (For Pump EFF-1 and Pump EFP-2) o Steam line valves MSV-55 and MSV-56 not open.
o EFW/MFW cross connect valves FWV-34 and FWV-35 not closed.
o All motor operated valves in EFW system not in proper position.
2.2.7 Indication As a minimum, the following indication shall be provided to the operator by emergency feedwater initiation and control (EFIC) or other plant instrumentation.
o Low range SG level. (For SG A and SG B) o Operate range SG level. (For SG A and SG B) o Key valve positions.**
o Water source inventory.
o Control system status (level setpoint selected).
o Steam pressure of each SG.
o EFW pump status indication.
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o Indications needed to check the status of EFW support systems.
o Additional primary system indication as required to monitor systems functions and operations.
o status of the EFIC system (bypass, test, tripped, etc.)
- Direct position indication (e.g., valve ste=
position) shall be provided for the following automatically operated valves and-all remote manual power operated valves: ETV-1, ETV-2, EFV-ll, EFV-14, EFV-32, EFV-33, EFV-55, ETV-56, EFV-57, EFV-58, FWV-34, TWV-35, MSV-55, MSV-56, ASV-5. Local manual valves in the flow path shall be locked open. Strict administrative of these valves.
control should be exercised over the use 2.2.8 Physical Seoaration System components and piping shall have sufficient physical separation or shielding to protect the essential portions of the system from the effects of internally and externally generated missiles.
Functional capability of the system shall also be assured for fires and the maximum probable flood.
i 2.2.9 Fluid Flow Instabilities The system design shall preclude the occurrence of fluid flow instabilities; e.g., water hammer, in syster inlet piping during normal plant operation or during upset or accident conditions.
2.2.10 Ooerational Testina Provisions shall be made to allow periodic operational testing.
2.2.11 Water Chemistry The requirements of the B&W Water Chemistry Manual, BAW-1385,_shall be met. The normal water source shall meet the requirements in Table 2-1.
2.2.12 Power The following valves require battery-backed DC power:
EFV-1, EFV-2, EFV-ll, ETV-14, EFV-32, ETV-33, MSV-55, MSV-56, ASV-5, ASV-204, ETV-55, ETV-56, EFV-57 and EFV-58.
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2.2.13 Interface with Valve and Pume Controllers All valve and pump controllers shall be designed such that signals from the EFIC system will override any other control signals. Also, when an EFIC signal is removed, the controller design shall be such that valves (other than the EVW control valve) will not change position and pumps will not change state withcut a specific manual command. When the vector logic clcse command to the EFW control valve is removed, the control valve shall be positioned as required by the EFW control system or the manual control as selected.
2.3 Codes and Standards The EFW system shall consider the requirements of the following codes and standards:
A. General Design Criterion 2*, Design Bases for Protection Against Natural Phenomena, as related to structures housing the system and the system itself being capable of withstanding the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, and floods.
B. General Design Criterion 4*, Environmental and Missile Design Bases, with respect te structures housing the system itself being capable of withstanding the effects of external missiles and internally generated missiles, pipe whip, and jet impingement forces associated with pipe breaks.
C. General Cesign Criterion S*, Sharing of Structures Systems and Components, as related to the capability of shared systems and components i
important to safety to perform required safety i functions.
D. General Design Criterion 19*, Control Room, as related to the design capability of syster l
instrumentation and controls for prompt hot i shutdown of the reactor and potential capability l for subsequent cold shutdown.
I i E. General Design Criterion 44*, Cooling Water, to assure:
(1) The capability to transfer heat loads frcr the reactor system to a heat sink under bcth l normal operating and accident conditions.
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(2) Redundancy of components so that under accident conditic41s the safety function can be performed asstining a single active -
component failure.' (This may be coincident with the loss of offsite power for ceJtain j t
events.) '
(3) The capability to isolate components, subsystems, or piping if required so that the system safety function will be maintained.
F. G'eneral Design Criterion 45*, Inspection of cooling' Water System, as related to design y provisions made to permit periodic inservice inspecticn of system components and equipment. ,
w G. General Design Criterion 46*, Tesjing ol' C cling i Water System, as related to design provisions made to permit appropriate functional testing of~the ,
system and components to assure structural-integrity and leak-tightness, operability nnd performance of active components, and capabili'ty of the integrated system to function as intended during normal, shutdown, and accident conditions.
H. Reculatorv Guides 1.22* Periodic Testing of Protection Syster Actuation Functions, Feb. 1972 1.26* Quality Group classifications and ',
Standards for Water, steam and Radioactive Umste containing Components, Rev 3, Sept. 1S78 1.29* Seismic Design Classification, Rev. 3, Sept. 1978 l'.47 Eypassed and Inoperable . Status' Indication, May 1973
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1.53 Application of the Single Failure Criterion, June 1973 1.62 , Manual Initiation of Protect 2ve Actions, Oct. 1977 '
1.75 Physical Independence of Elect ical systems. Rev. 2, Sept. 1978 1.102 Floyd Protection'for Nuclear Power ,
Plants, Rev. 1, Sept. 1976 Page 10 ,
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I. IEEE Standards s
279-1971* Criteria for Protection Systems for Nuclear Power Generating Stations (for initiation portions of EFW System) 323-1971* General Guide for Qualifying Class I Electrical Equipment 338-1971 Trial Use Criteria for Periodic Testing of Protection Systems 344-1971* Seismic Qualification of Class 1E Electrical Equipment 379-1972 Trial Use Guide for the Application of the Single Failure Criterion 384-1974 Separation of class IE Equipment and Circuits
- As a minimum, B&W recommends that these standards be met.
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i TABLE 2-1 OTSG Emercency Feedwater Chemistry Recuirements pH at 77F Same as normal requirementI ")
Dissolved oxygen (0 2)
OTSG at <i250 F No requirement (see hydrazine)
OTSG at > 250 F Normal 7 ppb max Upset 100 ppb max for a period not to exceed 1 week Total iron 100 ppb max e Hydrazine F Catalyzed.hydrazine OTSG at < 250 F Added to at least 300% of Stoichiometric oxygen concentration OTSG at > 250 F 20-100 ppb residual Cation Conductivity 1.0 mho/cm, max for a period not to exceed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> i
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8.5-9.3 at 77 F - with austenitic stainless steel feedwater heater tubes and stainless steel or copper-nickel reheater tubes.
9.3-9.5 at 77 F - Carbon steel feedwater heater tubes or combinations of carbon steel and stainless steel feedwater 4
and/or reheater tubes.
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DESIGN DESCRIPTION 3.0 3.1 Summary Descriction The EFW system consists of two interconnected trains, capable of supplying emergency feedwater (EFW) to either or both SGs from either of two water sources under automatic or manual initiation and control. A piping and instrumentation diagram is included as Figure 3.1-1 of this report.
The system pumps (EFW pumps) take suction from either the condensate storage tank or from the condenser hotwell and discharge to the SGs. In the flow path between the EFW pumps and the SGs there are isolation valves, check valves, control valves, flow instrumentation, and pressure instrumentation to control the flow of EFW to the SGs. The fluid syster design is described in Section 3.2. The instrumentation system design is described in Section 3.4.
3.2 Fluid System Desian The EFW system is designed as two interconnected trains with redundant components. Figure 3.1-1 depicts the piping and instrumentation diagram.
3.2.1 Suction The primary water source for the EFW trains is the Seismic Category I condensate storage tank, CDT-1.
Water is supplied from this tank through a common S inch line which is then split to provide two separate 6 inch lines containing locked open valves EFV-3 and ITV-4 at the pump suction inlets.
A reserve of 150,000 gallons is maintained within the tank and is verified by redundant, safety grade leve' indication in the control room. This volume of water will remove Decay Heat (plus RC pump heat for 2 pu=ps) for approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. This volume will also be sufficient to remove DH plus pump heat for 2 RC pumps plus cooldown to the DER system cut-in temperature in approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Low level alarms are provided to alert the operator to perform a suction transfer.
The main condenser hotwell is the main alternative suction source available for the EFW system. Separate 8-inch lines with normally closed DC-powered valves EFV-1 and EFV-2 draw suction through a common E-inch line with locked open manual valve EFV-36 and check Page 13 l
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valve. The DC-powered valves are interlocked such that they can be opened only if at least one of two DC-powered vacuum breaker valves is open.
For extended periods of EFW system operation with a loss of offsite power, an additional water source can be made available.
3.2.2 Pumos and Discharce Cross-Connect EFW Train B pump, EFP-2,-is a turbine driven pump with a rated capacity of 740 gpm at 1300 psig with a design recirculation flowrate of 200 gpm with the pump discharge closed. EFW Train A pump, EFP-1, is a mctor-driven pump which has the same rated capacity and recirculation flow as the Train B pump.
The Train A and B pumps discharge through check valves and manual operated stop-check valves (the electric power has been disconnected) into 6-inch cross-connected discharge lines. The separate cross-connects contain normally open motor operated valves EFV-ll and ETV-33. These cross-connects permit either pump to feed either or both steam generators.
3.2.3 Emeraency Feedwater Flow Control Valves The flow of EFW to each SG is controlled by normally-open modulating solenoid motor operated control valves in parallel paths (EFV-55, EFV-56, EFV-57 and ETV-58).
These control valves are designed to fail open.
Initiation and control instrumentation for these valves is described in Section 3.4.
3.2.4 Steam Generator EFW Isolation Valves Each steam generator can be isolated from EFW flow by normally-open motor-operated valves (ETV-11, EFV-14, EFV-32 and EFV-33). These valves are located in the parallel lines upstream of the EFW control valves.
They fail 'as-is' upon loss of power. Initiation and control instrumentation for these valves is described in Section 3.4 of this report.
3.2.5 Recirculation and Test Lines Recirculation lines are connected to the discharge piping of the EFW pumps. Recirculation for pu=p protection is accomplished with normally open flow paths to the condensate storage tank consisting of small lines with check valves and locked-open manual valves.
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e l EFW pumps can be operability tested using the normal recirculation flow paths to confirm the pump and pump drive capability to operate and produce the required discharge pressure. EFV-7 and ETV-8, or EFV-ll, EFV-14, EFV-32 and EFV-33 will have to be closed to perform this testing.
3.2.6 Steam Sucelv for the EFW System Turbine Steam supply for the EFW pump EFP-2 turbine is obtained from both steam generators through six-inch lines containing check valves MSV-186 and MSV-187, and normally-open DC motor operated stop-check valves MSV-55 and MSV-56. The check valve and motor operated valve provide redundant isolation capability to preclude blowing down the good steam generator in the event of steam line or feed line break. Downstrear of these valves the lines join to form a common supply to the pump turbine. Upstream of the turbine are normally redundant, normally closed DC motor operated valves ASV-5 and ASV-204. A description of the controls for these valves is contained in Section 3.4. An alternate steam source is provided from the auxiliary stear system which is tied to fossil fired Crystal River Units 1 and 2. This backup steam source is manually valved into service when required.
Turbine exhaust is vented to the atmosphere.
3.3 Succortine Systems The EFW turbine driven pump and turbine are self-contained entities without dependencies on secondary support systems. The bearings on the turbine and pump are lubricated by slinging oil from reservoirs near the bearings. Lube oil cooling is accomplished by heat transfer to the pumped fluid.
The EFW motor driven pump and pump motor bearings are lubricated by slinging oil from reservoirs near the bearings. Lube oil cooling is provided by the nuclear service closed cycle cooling system. Two of the five cooling water pumps receive diesel-backed power.
l 3.3.1 Power The two EFW trains are powered from diverse power l sources. EFW pump EFP-2 is turbine driven and EFW pump l EFP-1 is AC power motor driven with back-up power frer l the diesel generator. Valves EFV-3, EFV-4, EFV-7 and EFV-8 are disconnected from the AC power source and are locked open.
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To ensure EFW flow in the event of a loss of all AC power, the turbine driven pump train derives its power from the steam generators for the pump and from a battery-backed DC bus for its steam supply valves.
Valves EFV-2, EFV-11, ETV-32, ETV-57 and ETV-58 are assigned to Battery 'A'. Valves ETV-1, EFV-14, EFV-33, EFV-55, EFV-56, MSV-55, MSV-56, ASV-5 and ASV-204 are assigned to Battery 'B'.
3.4 Instrumentation Descriotion It should be noted that all setpoints and values used in the following discussion are approximate and are given for purposes of illustration.
The emergency feed initiation and control system (ET:C) is an instrumentation system designed to provide the following:
- 2. Control of EFW at appropriate setpoints (approx.
3, 20 and 31.5 feet),
- 3. Level rate control when required to minimize overcooling,
- 4. Isolation of the main steam and main feedwater lines of a depressurized steam generator,
- 5. The selection of the appropriate steam generator (s) under conditions of steamline break or main feedwater or emergency feedwater line break downstream of the last check valve,
- 6. Termination of EFW to a steam generator on approach to overfill condition, and
- 7. Control of atmospheric dump valve to a predetermined setpoint.
The emergency feed initiation and control syster (ETIC; is illustrated in Figures 3.4-1 thru 3.4-9. Figure 3.4-1 illustrates the EFIC organization while the remaining figures illustrate the individual logics that comprise the system. The interface of the EFIC with the secondary plant is illustrated in Figure 3.1-1.
The EFIC - see Figure 3.4 consists of four channels (A,B,C, & D). Each of the four channels are provided with input, initiate, and vector logics. Channels A and B also contain trip logics and control logics.
Page 16
- l l
I Each channel monitors inputs by means of the inpu*
logic, ascertains whether action should be initiated by means of the initiate logic and determines which SGs should be fed by means of the vector logic.
Channels A and B monitor initiate signals from each of the four initiate logics by means of the trip logics to a
transmit trip signals when required. Channels A and B also exercise control of emergency feedwater flow to the SG by means of control logics to maintain SG level at prescribed values once EFW has been initiated. In addition, Channels A and B also monitor SG A and B overfill signals originating in the Channel A, B, C and D initiate logics. By means of trip logics, Channels A and B terminate emergency feedwater to a steam generator that is approaching overfill.
3.4.1 Inout Locic The input logic, depicted in Figure 3.4-3a, 3.4-3b, and 3.4-3c, is located in each of the channels. The input logic:
- 1. receives analog channel input signals,
- 2. provides input buffering as required,
- 3. compares analog signals to appropriate setpoints to develop digital signals based on analog values,
- 4. provides for the injection of test stimuli,
- 5. provides buffered Class 1E signals and isolated non-lE signals, and
- 6. provides signals to the remaining channel logic.
3.4.2 Initiate Locic I
The initiate logic, depicted in Figure 3.4-4 is located in each channel. The initiate logic derives its inputs from the input logic and provides signals which resul:
in the issuance of trip signals via the trip logics in Channels A and B.
The initiate logic issues a call for EFW trip (to the trip logic) when:
- 1. all four RC pumps are tripped,
- 2. both main feedwater punps are tripped, Page 17
4
~
- 3. the level of either steam generator is low,
- 4. either steam generator pressure is low.
Other functions of the initiate logic are:
- 5. provide for manually initiated individual shutdown bypassing of RC pumps, and SG pressure initiation of EFW as a function of permissive conditions.
The bypass (es) are automatically removed when the permissive condition terminates.
- 6. Provide for maintenance bypassing of an EFIC initiate logic.
3.4.3 Trio Locic The trip logic is illustrated in Figure 3.4-5. The trip logic of the EFIC employs a 2(1-out-of-2) format.
This format provides for easy one step testing from input logic test switches to the initiated controllers.
Testing is facilitated by locating the AND portion of the 2(1-out-of-2) logic in the relay racks. A characteristic of coincidence logic systems is that a test stimuli inserted at the input propagates to the first AND element of the system and no further. Since i the first AND elehent of the EFIC is in the relay
! racks, test stimuli inserted at the input logic will be propagated to the relay racks and then to each controller. EFIC testing philosophy is discussed in Section 3.4.6.
The trip logic is provided with five 2(1-out-of 2) trip
! networks. These networks monitor the appropriate i outputs of the initiate logics in each of the channels and output signals for tripping:
- 1. emergency feedwater, Page 18
- 2. SG A main steamline isolation.
- 3. SG B main steamline isolation.
It should be noted, for the later discussion of the vector logic, that the trip logic outputs a signal when a2 (1-out-of-2) trip of EFW occurs. Also, note the presence of the vector enable switch.
It should also be noted that the EFW trip logics are input by the Emergency Safety Features Actuation System (ESFAS) HPI trip signals to assure that EFW is initiated coincident with emergency core cooling activation.
Refer to Figure 3.4 trip logics are contained in Channels A and B only per the two train EFW system.
For each trip function, the trip logic is provided with two manual trip switches. This affords the operator with a means of manually tripping a selected function by depressing both switches. The use of two trip switches allows for testing the '. rip switches and also reduces the possibility of accidental manual initiation.
Once a trip of the trip bus occurs, the trip is latched. A manual reset switch is provided for breakdown of the latch. Once a trip occurs, the trip can only be removed by manual reset action following return of the initiating parameter to an untrip value except as described in the next paragraph.
So that the operator may resume manual control of EFW initiated devices following a trip, each trip logic is provided with a manual pushbutton, operation of the manual pushbutton:
- 1. will have no effect on the trip logic so long as a trip condition does not exist.
- 2. will remove the trip from the trip bus only so long as the switch is depressed in the case of a one half trip (either bus but not both tripped).
This allows for testing the manual function.
Page 19
. 3. will remove'the trip from both busses so long as a full trip (both busses are tripped) exists. This is accomplished by means of latching logic.
Initiation of the manual function also breaks the trip latches so that, if the initiating stimull clears, the trip logic will revert to the automatic trip mode in preparation for tripping if a parameter returns to the trip region.
Trip signals are transmitted out of the EFW by activating a relay thereby gating power onto trip busses. In this manner, the EFIC provides power to energize the control relays whose contacts form the AND gates in the controllers.
3.4.4 Vector Loaic The vector logic - Figure 3.4 appears in each of the EFW channels - Figure 3.4-1. The vector logic monitors:
- 1. SG pressure signals,
- 2. SG (A and B) overfill signals, and
- 3. EFW trip signals (vector. enable) originating in Channel A and B trip logics.
The vector logic develops signals for open/close control of steam generator A and B emergency feedwater valves.
The vector logic outputs are in a neutral state (neither open or closed) until enabled by trip signals (vector enable) from the channel A or B trip logics.
Once enabled, the vector logic will issue close coLaands to the valves associated with any SG for whi:P an overfill signal exists.
Note the EFW overfill limit may be manually bypassed.
Manual bypass can only be initiated under permissive conditions of EFW trips in Channel A and/or B.
Page 20 i
When enabled and with no overfill signals present, the valve open/ close commands are determined by the relative values of steam generator pressures as follows:
SG A Valve SG B Valve Pressure Status Command Command SG A & B > Setpoint Open Open SG A > Satpoint & SG B < Setpoint Open Close SG A'< Setpoint & SG B > Setpoint Close Open SG A < Setpoint & SG B < Setpoint and SG A & B within 100 psi Open Open SG A 100 psi > SG B Open Close SG B 100 psi > SG A Close Open 3.4.5 Control Loaic The control logic is depicted in Figure 3.4-2.
For each SG (A and B) there are two controls which are selectable by transfers T1 and T6 respectively. The three foot level setpoint control is automatically selected when an EFW trip occurs with one or more i reactor coolant pumps operating. A level rate control with a twenty foot setpoint is selected when an EFW trip occurs with no reactor coolant pumps operating.
The three foot level control requires no explanation.
However, the rate control is more involved.
The characteristics of the rate limited follower are important in the following discussions. As the level signal changes, the rate output of the follower will follow it exactly so long as the rate of change does not exceed the predetermined rate limit values. The l rate limit values given (8 inches per minute for l increasing level rates and 200 inches per minute for l decreasing level rates) are approximate for purposes cf l illustration. (The rate limit for increasing levels is variable between 2 to 8 inches per minute as a functier of steam generator pressure). If level rate is increasing at greater than eight inches per minute, the i output of the rate limited follower will increase at eight inches per minute. Once the rate of increase decreases to eight inches per minute or less the output rate of increase will follow the input rate of I Page 21 1
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. _ _ . - . . , . _ _ , , . . . , - . . . _ . -_ ..,~,... _.-._ , - , _ _ _ _ . . _ . _ _ _ _ . . _ _ . _ . . _ _ . . . _ _ . _ _ . .._ . . _ . _ . - . _ _ .__
o increase. The function is similar for decreasing level except that the rate limit is approximately 200 inches per minute. A side benefit of the rate limited follower is attenuation of noise whose effective rate is in excess of eight inches per minute or 200 inches per minute respectively.
Reference Figure 3.4 with no RC pumps operating the twenty foot setpoint will be selected and applied to one input of the low selector. As SG level falls, the output of the rate limited follower will lag actual level by twelve inches (twelve inch bias added to the level signal in the summer) . When the rate limited signal (level plus twelve inches) becomes less than twenty feet, the rate limiter signal will appear at the subtractor (delta). The output of the subtractor will be approximately a negative one foot level error signal which will start opening the control valve ever wider thru the proportional plus integral. The increasing flow should halt the drop in level and ultimately start the level to increase toward the setpoint.
If the level increase is more rapid than eight inches per minute, the error signal out of the subtractor will decrease. This is due to the fact that the direct level input to the subtractor is not rate limited while the rate limited signal is. This action will control the control valve so that the rate of approach to the setpoint does not exceed eight inches per minute.
When level exceeds nineteen feet, the low selector will lock the twenty foot setpoint into the subtractor.
During the last foot of level increase the error output of the subtractor will gradually reduce.
Transfer T4 is provided to allow for selection of hand control from either Main control Board or Remote Shutdown Panel.
See Figure 3.4 transfer logic T3 allows for selection of a manually inserted setpoint (illustrated as a thirty one and one half foot setpoint). The logic is arranged so that manual may be selected before and after an EFW trip. However, the twenty foot setpcint will automatically be selected on the occurrence of an EFW trip.
See Figure 3.4-2 -
transfer logics T2 and T7 allow for selection of hand control of emergency feedwater control valves before and after an EFW trip. However, automatic operation will automatically be selected on the occurrence of an EFW trip.
Page 22
In addition, EFIC channel A is provided with a pressure control loop for the steam generator A atmospheric dump valve. EFIC channel B is provided with a pressure control loop for the steam generator B atmospheric dump
' valve. Transfer T4 provides transfer of ADV control to a location outside the main control room.
f The steam generator atmospheric dump valve control logic requires no explanation.
3.4.6 EFIC Trio Testina Figure 3.4-7 illustrates the trip philosophy of the EFIC in simplified form for one EFIC trip function (i.e., EFW trip). For purposes of the following discussion, the test pushbuttons associated with each bistable are capable of forcing the bistable input into the trip region. The bistables e= ploy a low dead band so the bistable will reset once the pushbutton is released.
Complete trip testing (input to auxiliary trip relays) may be initiated from the input logic in each of the channels. Depressing the pushbutton in Channel A will trip the Channel A bistable aid:
- 1. The Channel A initiate ?.ogic will transmit initiate signals to bota the Channel A and B trip logics.
- 2. The Channel A and B trip logics will half trip (trip one of the two trip busses.).
- 3. The Channel A and B trip logics will latch in the half trip. The half trip will be retained after reset of the bistable. This tests the latching circuit.
- 4. Each auxiliary trip relay receiving the half trip will acknowledge the half trip by transmitting a test confirnation signal.
- 5. A full complement of test confirm signals will satisfy the AND gate in both Channel A and B. The result is that the confir= lamps will indicate test success.
- 6. The trip logic reset switches can not be depressed to reset the half trip. The confirm lamp should go out.
- 7. If some but not all auxiliary trip relays were to Page 23
respend due to a malfunction, the confirm lamp will flash.
- 8. The foregoing tests may be conducted from each channel in turn to test the ability to transmit trips from all channels.
- 9. The foregoing tests may be conducted for all trip functions from all channels for complete trip testing.
- 10. Tests as described above may also be conducted by use of the local and remote manual trip and reset switches.
NOTE: The utilization of one out-of-two taken twice logic allows for the foregoing test philosophy while minimizing the probability of inadvertent initiation.
3'.4.7 EFIC Sicnal ADolication Figure 3.1-1 illustrates the application of EFIC signals to a simplified emergency feedwatar system.
Salient features of the arrangement are:
- 1. The channel A EFW trip signal starts the electric emergency feedwater pump. The Channel B trip logic admits steam to the turbine powered emergency feedwater pump. With this arrangement, at least one pump will be started with a single failure of the A or B trip logics.
Also, given a failure of channel A, B, C, or D initiate logics, both pumps will be started due to the 2(1-out-of-2) character of the trip logic.
The cross-connects between the discharges of the two emergency feedwater pumps allows either pu=p to supply feedwater to both SGs.
- 2. If the cause of the EFW trip is low SG pressure in SG A, EFW will be tripped as in 1 above. In addition, the trip logics in channels A and B will issue SG A main steamline and main feedwater isolation trip signals. The channel A and B trip logics will redundantly isolate SG A main feedwater. With the occurrence of low pressure in SG A main feedwater to that generator will be terminated in the presence of a single failure.
- 3. Isolation of SG B main steam and main feedwater lines occurs in the same way as described in 2 Page 24
__ ___ _ _____ _______________ _ _____________J
above for SG A except that the channel A and E SG B main feedwater and main steamline trip logics are employed.
- 4. Given the condition where both SG pressures are low, the events described in both 2 and 3 above will occur.
- 5. The emergency feedwater path to each SG consists of parallel control valves and parallel isolation valves. This allows feeding when required in the presence of a single valve failure. It also allows closure of the flow path when required in the presence of a single failure. Since each of the four valves receives vector close signals from different channels, the path will be closed when required by the vector logics in the presence of the failure of a single vector logic.
In the open direction, the isolation valves receive open vector commands, from channels C and D, when feeding of the SG is required. The control valves, under these conditions will open as dictated by the control logics in channels A and B. In this way, a generator will be fed when required in the presence of a failure of channel A, B, C, or D.
3.4.8 OTSG Level Sensine Figure 3.4-8 contains the proposed arrangement for O!SG level sensing. The acceptability of this design will depend on the accuracy of the measurement. Allowable instrument error requirements to render this design acceptable are given in Appendix B.
To provide for low level control and initiation signals for the emergency feedwater, four differential pressure transmitters (dP transmitters) will be added. The sensing lines for these transmitters will be connected between the unused existing level sensing connections located 277 inches above the top face of the lower tube sheet and manifolded to the existing low level taps at 6" inches above the top face of the lower tube sheet.
To provide high level control and overfill protection signals, four dP transmitters will be added. The upper sensing connections will be manifolded with the upper sensing line of the existing operating range level transmitters. The lower sensor connections will be manifolded with the lower sensing line of the existing operating range level transmitter.
Page 25 l
4.0 SYSTEM LIMITS, PRECAUTIONS AND SETPOINTS 4.1 Limits and Precautions 4.1.1 EFW Flow Limits Maximum allowable flow - 1840 gpm/OTSG Minimum allowable flow - 740 gpm to one or both OTSGs 4.1.2 EFW Pume Suction Pressure EFP-1 minimum NPSH - 27 feet EFP-2 minimum NPSH - 34 feet _
4.1.3 System Limits (Desien)
Pressure -
Temperature - 1600gsig 465 F 4.1.4 Minimum Pume Recirculation EFP 200 gpm EFP 200 gpm Note: This flow requirement is during testing of the pumps when the discharge valves are closed so the pumps do not deadhead.
4.2 Setooints All setpoints given in this section and defined as
" nominal" are instrument calibration points.
Instrument string errors as defined in Appendix B were used in the analyses to determine the conservative maximum and minimum setpoint values. Tne maximum and minimum setpoints represent the earliest and latest assumed actuation point for use in analysis.
For the purpose of this discussion, " LEVEL" refers to the equivalent height of a saturated water column (1065 psia) referenced from the top of the lower tube sheet.
Page 26 i
o 4.2.1 Low SG Level EFW Initiate Setooint This is a protective setpoint designed to initiate EFW flow to a steam generator following loss of main feedwater flow. The low range level instrumentation is used to monitor low level in the steam generators. For setpoints see Table 4.2-1.
4.2.2 EFW Control Level (3 Foot Level) Setooint This is a level control setpoint designed to be automatically selected following initiation of EFW if one or more reactor coolant pumps are providing forced circulation. The low range level instrumentation is used to monitor steam generator level at this point and to provide signals to the EFIC control system. For setpoints see Table 4.2-1.
4.2.3 Natural Circulation Control Level (20 Foot Level)
Seccoint This is a level control setpoint designed to be automatically selected following initiation of EFW if all four reactor coolant pumps are tripped. For 177 FA plants 20 feet of steam generator level provides a thermal center in the steam generator at a higher elevation than that of the reactor. Controlling steam generator level at a minimum level of 20 feet insures natural circulation of the reactor coolant system fluid. The full range level instrumentation is used to monitor steam generator level at his point and to provide signals to the EFIC control system. For setpoints see Table 4.2-1.
4.2.4 Steam Generator Overfill Setooint This is a protective setpoint designed to automatically terminate EFW flow to a steam generator. This serpoint is required to prevent steam generator level from increasing to a level at which emergency feedwater would flow into the main steam lines. Tnis setpoint can be manually bypassed to allow the setpoint .
described in Section 4.2.5 to be reached. The high range level instrumentation is used to monitor steam generator level at this point. For setpoints see Table 4.2-1.
4.2.5 ECCS Fill Limit Setooint (31.5 Feet Level)
This is a level control set point designed to be manually selected following a LOCA. This setpoint will establish a steam generator feedwater level wnich will Page 27
_-_ _ _ - - _ _ - _____ O
support steam condensation natural circulation. To preclude terminating emergency feedwater flow before this setpoint is reach, the steam generator overfill setpoint described in Section 4.2.4 must be manually bypassed. The high range level instrumentation is used to monitor steam generator level in this region. For setpoints see Table 4.2-1.
4.2.6 Low Steam Generator Pressure Setooint This is a pressure setpoint designed to automatically isolate the main steam lines and main feedwater lines to the affected steam generator. This setpoint will isolate the steam generator only if one steam generator is affected. The other steam generator will not be isolated. If both steam generators are below this setpoint the EFIC system will determine which steam generator to supply and which to isolate. Pressure instrumentation string requirements are given in Appendix B. For setpoints see Table 4.2-1.
4.2.7 Steam Generator Differential Pressure Setcoint This a pressure setpoint designed to automatically determine, by comparing the difference in steam generator pressures, which steam generator is to be isolated and which steam generator is to be fed.
Pressure instrumentation string requirements are given in Appendix B. For setpoints see Table 4.2-1.
4.2.8 Atmoseheric Dume Valve operatino Setcoint This is a pressure setpoint designed to automatically open the atmospheric du=p valves to relieve steam generator pressure. This setpoint is lower than the steam generator relief valve lift point and will therefore decrease the frequency of challenges to the relief valves. The control system provides the operator with the capability to manually override this setpoint. Pressure instrumentation string requirements are given in Appendix B. For setpoints see Table 4.2-1.
Page 28
=' 5.0 OPERATION The EFW is in a standby mode during normal power operation. Manual action will be required to remove the initiate bypass features of the EFIC System during various modes of operation.
5.1 Heatuo from Cold Shutdown to Hot Standby Before heating up from cold shutdown, the operator should verify the status of the EFIC. All signals should be bypassed with the exception of the low OTSG level initiate of EFW and the high OTSG level overfill termination.
When the first RC pump is started, the " Loss of 4 RC Pumps" initiate signal may be manually bypassed. This is accomplished by depressing the " Bypass Reset" button located in each of the EFIC cabinets. If the bypass is not manually reset, it will be automatically reset when the plant reaches 10% power. As the plant begins heating up, the bypass of the low OTSG pressure signal will be reset. This bypass reset will automatically occur for both OTSG's when the first steam generator reaches 750 psig. The operator should ensure that both steam generators are above 600 psig before the bypass reset occurs.
5.2 Hot Standbv to Full Power At hot standby conditions, all trip functions should be active except the MFW pump trip. As power is increased, the MFW pump trip will automatically become active at about 20% power. The logic for this function is located in the NI/RPS. No operator actions are required.
l When reducing power from full power to hot standby, nc i operator actions are required. The MFW pump trip will be automatically bypassed in the NI/RPS when power is reduced below approximately 20%. The operator should confirm that this action has been taken.
5.3 Cooldown from Hot Standby to Cold Shutdown During the cooldown, two shutdown bypasses must be implemented. The first is the low steam pressure shutdown bypass. When both steam generators are below 750 psig, this bypass may be implemented by depressing the low steam pressure shutdown bypass buttons located Page 29
e in the EFIC cabinets or remotely on the MCR console.
One button in each of the four channels must be depressed. This action must be taken before either OTSG pressure reaches 600 psig.
The second shutdown bypass is for the " Loss of 4 RC Pumps" trip. This shutdown bypass may be implemented at any time after Power has been reduced below 10%.
However, for most operating conditions, it is recommended that this trip function remain active until after the Decay Heat Removal System has been initiated i and the system is ready for the last RC pumps to be tripped. As with the low steam pressure shutdown bypass, this action must be taken by depressing the Loss of 4 RC pumps Shutdown bypass buttons on the EFIC cabinets.
5.4 Wet Lavun Wet layup of a steam generator is required during plant
, shutdown to protect the OTSG tubes (see OP-608). The i
OTSGs are filled via the startup feedwater control valves using the FW booster pump. During fill, nitrogen is bled by throttling the vent valves to 1 maintain a nitrogen pressure of 2-5 psig. Wet layup of
! the OTSGs requires a level above the overfill setpoint.
The EFIC overfill setpoint can be bypassed and reset by following the instructions in SP-349 (EFW Overfill Bypass and Reset). Full wet layup is achieved when the water level reaches the upper.OTSG vents (>600" on the high range level indicator) . At this time the startup feedwater control valves are closed and the FW booster pump is secured. During wet layup the nitrogen pressure will be maintained at 5 psig.
I 4
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1 Page 30
- 6.0 CASUALTY EVENTS AND RECOVERY PROCEDURES 6.1 Casualtv Events As part of the design of the EFW system, consideration was given to handling the following casualties:
a) Loss of main feedwater (LMFW) b) LMFW w/ loss of offsite AC power c) LMFW w/ loss of onsite and offsite AC power d) Plant cooldown e) . Turbine trip with and without bypass f) Main steam line isolation valve closure g) Main feedline break h) Main steam line break / auxiliary feedwater line break i) Small break LOCA j) OTSG overfill 6.2 Desian Features to Miticate Effects of Casualty Events 6.2.1 Loss of Main Feedwater (LMFW)
Upon loss of all feedwater both EFW pumps are automatically initiated by the EFIC system. A minimur flow rate of 740 gpm, with a single failure, is sufficient to mitigate the effects of a LMFW with reactor power reduction and turbine trip. After initiation, the level will be automatically controlled to about 3 ft. The only operator actions are to confirm that EFW flow has been initiated and that a level has been established in both OTSG's.
6.2.2 Loss of Main Feedwater with Loss of Offsite AC Power Upon loss of offsite AC power (which causes a loss of the RC pumps), the EFW system is used to establish natural circulation. Both EFW pumps are automatically fnitiated by the EFIC system. The level rate control system will automatically raise the level in the OTSG's to about 20 ft. at a rate of about 8"/ minute. The high auxiliary feedwater injection point in the steam generators provides a high thermal center which will establish natural circulation even with a low steam generator level. For a high decay heat event, the level should increase to 20 ft. at 8"/ minute without requiring any operator action. For lower decay heat event, the excess EFW injection will begin to quench the steam and steam pressure in the OTSG will drop.
This decrease in OTSG steam pressure (and saturation temperature) will continue to overcool the primary Page 31
system. The EFIC is designed to automatically throttle back EFW flow as steam pressure drops. The flow will be throttled to a minimum of about 2"/ minute level increase when steam pressure drops to about 900 psig.
This feature should minimize the potential for overcooling. For very low decay heats, the operator may have to take manual control of the EFW system and further reduce EFW flow to keep from losing pressurizer level. The design basis for the EFIC is to allow a minimum of 10 minutes with no operator action for all cases. It is anticipated that either no operator action will be required, or a time well in excess of 10 minutes will be available for operator action.
6.2.3 Loss of Main Teedwater with Loss of Onsite and offsite AC Power This event is not a design basis for the plant, however the EFW system is designed to supply a minimum of 740 gpm flow with the loss of both onsite and offsite AC power. All IFIC controls are powered by battery-backed vital AC power. All valves required to supply flow are powered from DC busses. The turbine train of EFW should start and raise level to 20 ft. as described in Section 6.2.2.
6.2.4 Plant Cooldown The EFW system is capable of being used to assist in a plant cooldown. The plant, however, was not designed for a cooldown with only safety grade systems. The motor-driven EFW pump can be used with the atmospheric dump valves to cool the plant down to the Decay Heat Removal System cut-in temperature. Since this is not a design basis requirements for this system, specific calculation of time to cooldown the plant using atmospheric dump valves have not been made.
6.2.5 Turbine Tric With and Without Bvuass This event does not affect the EFW system unless MFW fails. In which case, the loss of MFW event in Section 6.2.1 described the behavior of the ETW system.
6.2.6 Main Steam Line Isolation Valve Closure Again this event does not affect the EFW system unless MFW fails.
Page 32
5*
- 6.2.7 Main Feed Line Break This break is a more abrupt case of LOFW and has approximately the same requirements for EFW flow. If the break is upstream of the last feedwater line check valve, the accident should proceed as the loss of main feedwater event described in 6.2.1. If the break is downstream of the last check valve, the steam generator will blow down to the containment. When the steam generator has depressurized below approximately 600 psi, the steam generator isolation logic will isolate the main feedwater and main steam lines to the affected steam generator. After isolation, the Vector Logic will supply EFW only to the intact steam generator.
The only required operator actions are to confirm that the proper automatic actions were taken.
6.2.8 Main Steam Line Break /Emeraency Feedwater Line Break The effect on the system from both of these transients is essentially the same. For smaller break sizes, the steam generator will not depressurize or will require a very long time to depressurize. No automatic action is taken for these cases. The operator must diagnose the problem and take appropriate manual actions. For break sizes that will depressurize the steam generator down to approximately 600 psig, the depressurized steam generator will be automatically isolated. Some break sizes and locations may cause both steam generators to depressurize below 600 psig and both will be isolated.
If the break is downstream of the isolation valve, both steam generators should repressurize. EFW will then be fed to both steam generators. If the break is upstream of the isolation valve, only one steam generator will repressurize. The Vector Logic will direct EFW only to the intact steam generator. The only required operator actions are to confirm that the proper automatic actions were taken.
6.2.9 Small Break LOCA For A Small Break LOCA (SBLOCA) event, the EFW system will be automatically initiated by an ESFAS signal.
Current procedure also requires that the RC pumps be tripped for a Small Break LOCA. Under these conditions, the EFIC system should automatically raise level at about 8"/ minute in the steam generators to the natural circulation setpoint of approximately 20 ft.
This fill process is expected to require approximately 30 minutes, unless the operator has further throttled the EFW system to avoid exceeding the 100 F/hr OTSG cooldown rate. During this time, current procedures Page 33
required that the operater diagnose the event to determine that it is a SBLOCA.
When this determination has been made, the operator is instructed to raise the OTSG level to approximately 31.5 ft. The purpose of raising the level is to assist in establishing steam 1 condensation natural circulation if part of the primary system is voided. The action to raise the level should 4
be taken while the OTSG is filling to 20 ft. During this time, there will be substantial EFW flows high in the OTSG. These flows will provide good heat transfer
- high in the OTSG.
! In order to raise the level to 31.5 ft., the operator i
must select the "95%" setpoint on the EFW control station. Selection of this setpoint will continue the filling of the OTSG at about 8"/ minute to the 31.5 ft j' level. A second action the operator should take is to bypass the EFW overfill protection. The setpoints for overfill termination will probably prevent filling the OTSG to the desired level if they are not bypassed.
- Bypassing these setpoints requires that the operator go to the EFW cabinets and depress the bypass button in
- each channel. This action cannot be taken from the EFW control station.
If filling the OTSG at some rate other than the one
- used in the EFIC system is required, the operator may take manual control of the EFW control valves. EFW can
!' then be manually controlled as required for a given situation.
6.2.10 OTSG Overfill
, An ETW overfill event is detected by an OTSG downcomer 4 level of 31 feet. The action taken is to close the EFW l isolation and control valves to the affected OTSG. For an EFW overfill event, however, the overfill protection i circuit will automatically return control to the EFIC l- when OTSG level has dropped to a reset setpoint of i about 28 ft. No operator action is required for an EFW j overfill. The operator should determine the cause of
- the overfill and correct it. Otherwise, the level will l cycle between the overfill setpoint and the reset i setpoint.
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a w.we,w,v-.r---ne...,~,,pwe -m-v,,-,,,n,, _.,-n.--,_-,w,_mm,,-.wn,,-,,,,--n _ -,--n.- __,,.,_m,---,-m_m.-..
L 7.0 TESTING AND MAINTENANCE The EFW System is designed to allow periodic testing during power operation. Routine maintenance activities, however, should be performed during plant outages. The technical specifications will allow one train of the EFW system to be inoperable for only a short period of time during power operation (typically 24 to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />). Therefore, most corrective maintenance must be performed with the plant shutdown.
7.1 Periodic Testina of the Fluid System The system design allows testing of the pumps and valves in the EFW system during power operation. The pumps can be tested by manually starting them and operating for at least 5 minutes with recirculation flow.
All automatic valves in the EFW syste= can be full stroke exercised during power operation without EFW pump operation. No system realignment is required to perform these valve tests.
7.2 Periodic Testinc of the EFIC TheEFICisdesignedtoallowtestingduringpoweh operation. One channel should be placed in
"=aintenance bypass" prior to testing. This will bypass only one channel of ETW initiate logic. The
" maintenance bypass" does not bypass the trip logics within the bypassed channel. An interlock feature prevents bypassing more than one channel at a time. In addition, since the EFIC receives signals from the NI/RPS, the maintenance bypass from the NI/RPS is interlocked with the EFIC. If one channel of the NI/RPS is in maintenance bypass, only the corresponding channel of the EFIC may be bypassed (e.g., channel A NI/RPS and channel A EFIC). Administrative procedures should be written to ensure that only corresponding channels of the EFIC and NI/RPS are placed in maintenance bypass at the same tire.
The EFIC is designed to be tested from its input terminals to the actuated device. A test of the EFIC trip logic will actuate one of two relays in the auxiliary relay rack. Activation of both relays is re-quired in order to actuate the end devices. The two relays are tested individually to prevent automatic actuation of the component. Testing of the sensor inputs to the EFIC will normally be accomplished with the plant at cold shutdown.
Page 35
9 r*
High Pressure Injection (HPI) inputs from the ESAS system may be bypassed only by the ESAS system at the ESAS actuation cabinets. A simulated input to the EFIC system can be generated by a keylock switch within the ESAS actuation cabinets.
M Page 36 k
, FIGURE 3.3-1 CRYSTAL RIVER UNIT
., SIMPLIFIED POWER SOURCE DIAGRAM STARTUP A ONER (NOTE I)
ES ES 4160 BUS 3A ) NC (NC 4160 BUS 3B I I I NO) NC) NO) NC) (NC (INC (INO 3 W S CW Z 4160/480
)4160/480 (NC ES BUS 3A ES BUS 36 NC MCC 3A-1 DUPLICATE FOR l VITIALS B & D l l l B Dj j __ __
NC) NC) NO NC NC); y y I ICS-V NNI-Y BATT IC CHGR55. .. .. ._
{A NEL!
3A I STATIC '
l INV. VITAL C NNI-X O
NC NC NOTES:
- 1. TWO ALTERNATE SOURCEE AVAILABLE MANUALLY UNIT 1/2 STARTUP XFMR DISCONNEC' WITHIN MINUTES 5 WITCH AND UNIT 3 AUX. XFMR WITHIN EIGHT HOURS.
Page 37
.y. g ,
a
, t,g , ').
,e -
yL FIGURE 3.3-2 -
" CRYSTAL RIVER UNIT 3' e' t SIMPLIFIED POWER SOURCE DIAGRAM s l DC LOADS 3 s ,.
a /
FROM MCC ,3A-l 'FROM'MCC 38-2 /3
-1 1 .i f. l' i 1 ? y, g:
.. J - },
1
) NC ) NC' NO; ,
NO ( NC ( l NC(l
\\ ,
BATT BATT BATT It BATT BATT "BATT -
CHGR CHGR CHGR \ CHGR CHGR . !s_CHGR f ( ,
NC NC NO NC NO) ( NC I .
l I I (l , I' 1
l j u .
- NC) NC) PANEL PANEL (NC (NC (NC (NC ,a 3A 3B
$ $i S OPDP-1A DPDP-IB @i @ @
i i --
i i
- a. a. a. -
t Q. c_
Q Q Q '
C Q Q Q. 0- Q. f_ 0- a.
O Q Q l l 'DPDP-3 A DPDP-3Bl l !
, Q O O
_ _ _)
~ EFV-2 EFV _
_y __,_._- _.,_
I i' i EFV-14 =-
= EFV-1I EFV-33 _
= EFV-32 ASV-5/ASV-204 7
= EFV-35 FWV-33
EFV-36 FWV-34
= EFV-57 MSV-55 -
= EFV-58 MSV-56 _
EFV-56 Page 33 EFV-55 .= _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/ l; ? ,
4$$F'0 FIGURE 3.3-3
/' ,
/
s"4 sis,PLIFIED POWER SOURCE DIAGRAM CRYSTAL RIVER 3
@ 1 !. AC VALVES c \ ;. ~
l' 's ', 'c , x- ,
( ,
i l
~
UNIT 3 AUX XFMR k,
\{- '
= UNIT 3
,(. ii' -
STARTUP
\
1p, 5 '
, .s ' -
XFMR T
4160 UNIT SUS"'3A
) NO ,
)NO 4160 UNIT t'
- BUS 3B
. s i,I 8
, , ' ['NC s
, j ',7 NC
- ' s\ s. ,,
2 i PLANT AUX 4160/480 % BUS _3 4160/480
'o \i
- y w ,i t
g
- (0 / /
/ >
h i NC NO '
jNO C TURBINE A'JX TURSINE Ad'X .
BUS 3B B U S 3 A,.' ',. . }:
- i. .
\..- T f'
JNG
) NC
~
. .', ,t ' TURBINE '
TURBINE
, MCC-3A MCC-38 i
)NCNC) I
')NC NC)'
,, fw f f f
. SPARE SPARE SPARE SPARE I
e s PAGE 39 .
Table 4.2-1 EFW SYSTEM SETPOINTS Normal Maximum Minimum Seteoint Descrintion Setnoint Seteoint Setcoint Low Steam Generator Level Initiate 6.00" 7.41" 4.56" EFW Control Level 24" N/A N/A Natural Circulation Control Level 279" 369" 279" Steam Generator Overfill Isolation 383" 383" 382" Emergency Core Cooling System Fill 369" 369" 354" Level Steam Generator Level High to 346" 383" 102" Rese Overfill Feedwater Isolation Logics Low Steam Generator Pressure 600 750 598 Initiate and Isolation Steam Generator Differential Pressure 125 137 13 EFW Valve Vectoring Atmospheric Dump Valve Open 1025 1035 932 Shutdown Bypcts 3:G Pressure 750 N/A N/A Rate Limit Follower:
A. SG Pressure 1800 psi 2 inches per minute N/A N/A
( R._800 psi i SG Pressure i 2 to 8 inches per N/A N/A
'050 psi min.(varying Linearly)
C. 1050 psi 2 SG Pressure 8 in. per minute N/A N/A i
i l
Page 40 I
.,=.,..r - - . . - , - - - - - - -m----, -. -.--m- c------- , - - - - - --. -,n- - - , , --- - - . - - - - - - - - - - - - , , -n
Table 4.2-1 cont.
EFW SYSTEM SETPOINTS Normal Maximum Minimum Setpoint Description Setootnt Setooint Setooint Proportional and Integral Controls in the Level Control Modules:
A. Integral (Repeat Rate) 3 repetition per min. N/A N/A (switch values of 0500)
B. EFW K2 (high range K2 = 2.71 N/A N/A proportional control) (switch values of 02710)
C. EFW Kg (low range Kg - 7.0 N/A N/A proportional control) (switch values of 07000)
Proportional and Integral Controls in the Atmospheric Dump Valve Control Module:
A. Integral (repeat rate) 2 repetitions per min. N/A N/A (switch values of 0333)
B. Proportional (gain) ADV K-5.0 N/A N/A (switch values of 05000)
Unfixed Biases A. Component C4 12 inches N/A N/A B. Component TS 0 inches N/A N/A C. Component C2 24 inches N/A N/A D. Component C18 1025 psig N/A N/A Note: All level setpoints refer to the equivalent height of a saturated water column (1065 psia) referencad from the top of the lower tube sheet. It should be noted that the lowest low range instrument sensing tap is at an elevation of 6" above top of lower tube sheet.
Page 41
. APPENDIX A TABUIATION OF DRAWING NUMBER VS. FIGURE NUMBERS FOR CRYSTAL RIVER-3 EFW SYSTEM FIGURE B&W DRAWING NUMBER NUMBER DRAWING TITLE 3.1-1 ll21232D Emergency Feedwater System (P&ID) 3.4-1 ll22969F EFIC Organization 3.4-2 ll22968E EFIC Logic 12- SG Control 3.4-3a 1122974C EFIC Logic l- Steam Generator A Level Input 3.4-3b ll22973C EFIC Logic 2- Steam Generator B Level Input 3.4-3c 1122972C EFIC Logic 3- Steam Generator Pressure 3.4-4 1122967C EFIC Logic 5- Initiate Logic 3.4-5 1122971E Trip Logic 3.4-6 ll22970C EFIC Logic 6- Vector Logic 3.4-7 1122966C EFIC Trip Test Philosophy 3.4-8 1121441C CM&D Equipment OTSG Level Sensing 3.4-9 1122965B EFIC Symbology APPENDIX A, Page A-1 1
APPENDIX B INSTRUMENTATION REQUIREMENTS
- 1. Low Panae Level Instrument Strinal
- a. Tap Elevations 6" & 277"
- b. Scale 0-150"
- c. Pressure 1200 psig
- d. Temperature 600 F
- e. Instrument String Errors: See Note 2 and 3
- e.1 Normal Operating Environment
- 13" e.2 Small LOCA Environment 215" Reference Leg Heatup -20"
- Design Break Environment 115" Refernce leg Heatup -28"
- 2. Mich Rance Level Instrument Strinal
- a. Tap Elevations 102" & 394"
- b. Scale 100" - 400"
- c. Pressure 1200 psig
- d. Temperature 600F
- e. Instrument String Errors: See Note 2 and 3
- e.1 Normal Operating Environment __ 6"
- e.2 Small LOCA Environment 115" Reference Leg Heatup -21"
- e.3 Design Break Environment t27" Reference Leg Heatup -30"
- 3. Full Rance Level Instrument Strinal This is a combination of low and high range instrumentation l 4. Pressure Instrument Strinasl i
- a. Span 0-1200 psig
, b. Response Time 1 second l c. Instrument String Errors: See Note 2 and 3
- col Normal Operating Environment 25 psi APPENDIX B, Page B-1
APPENDIX B cont.
- Normal Operating Environment - 80F to 140F/ LOO %RH
- Design Dreak Environment - 80F to 300F/ LOO % RH Radiation Dose Air (TID RADS) 1000 hrs = 2.1 x 108 Peak Building Pressure 50 psig 9 120 seconds Spray pH 7.5 to 10.0 Since no SLB analysis has been performed for the 177-FA plants the design break LOCA environment conditions were considered conservative and used for temperature, RH, Peak Building Pressure, and spray pH. The radiation dose used for the small LOCA environment is the requirement for the 205 FA plants and is therefore considered conservative since the 205-FA plant power level is higher than the 177-FA plant power level.
NOTES:
- 1. Level measurement to be density / pressure compensated over a pressure range of atmospheric to 1050 psig assuming a saturated volume of steam and water. Since the level measurement is density compensated, the unit " inches" refers to the actual level in the steam generator over the specified pressure range.
- 2. Actual string errors are found in B&W Document #32-1158577-00, "EFIC String Error" which is based on Hethodology Document #51-1158421-00.
- 3. The EFIC system is not required to perform during large break LOCAs. For error analysis, the energy released by Steam Line Break (SLB) and Feedwater Line Break (FLB) accidents is considered to be enveloped by small break LOCAs.
APPENDIX B, Page B-2
APPENDIX C EFW SYSTEM CONTROL VALVE REQUIREMENTS
- 1. Q331 cn Conditions
- a. Pressure 1725 esia
- b. Temperature 465F
- c. Maximum dP 9 shut-off 1725 esid
- d. Stroke time 10 sec. max.
- 2. Function / System Emergency Feedwater Control /EFWS
- 3. Oceration Modes *
- a. Flow _12_ gpm; Inlet Press / Temp 1450 esic/100F; Outlet Press / Temp 50 esic/100F
- b. Flow _12_ gpm; Inlet Press / Temp 1150 esia/100F; Outlet Press / Temp 1050 esic/100F -
- c. Flow 112_ gpm; Inlet Press / Temp 1150 esic/100F; Outlet Press / Temp 650 esic/100F
- d. Flow 112_ gpm; Inlet Press / Temp 1150 esic/100F; Outlet Press / Temp 1085 esic/100F
- Note: 1. Valve shall be capable of controlling at all points within the operating envelope.
- 2. Valve design which produces cavitation, affecting valve operation and/or seat leakage is prohibited.
- 4. Too Work and Accessories:
- a. Actuator - Modulating Solenoid Motor
- 1. Power: 125 VDC +15V -20V
- 2. Increase in signal input closes valve
- b. Failure mode - open
- 5. Code Classification
- a. Governing Code
- b. Code Class ASME Section ILI 3
- c. Issue Date & Addenda: That in effect at time of order APPENDIX C, Page C-1
O APPENDIX C cont.
- 6. Desian Life Cveles:
Full cycle - 2000 20% stroke - 4000 20%-80% stroke - 2000 I
- 7. Qualification
- a. valve actuator and essential electrical appurtenances shall be qualified to the requirements of IEEE-382, 1980.
- b. The valve and actuator shall be designed and qualified to operate during and after a seismic event.
- c. The controller is located in the control Building. The valve and actuator are located in the Intermediate Building and must be qualified to the following environmental conditions:
Valve / Actuator Controller col Temperature (F)
Normal: 115 75 Abnormal: 140 104 Accident: 340 N/A c.2 Pressure (psig)
Normal: 0 0 Abnormal: 0 0 Accident: 4.7 N/A c.3 Humidity (% RH)
Normal 90 32 Abnormal: 100 100 Accident: 100 N/A c.4 Radiation Conditions Integrated dose lx10 4
- N/A (rads, 40 yrs)
- Includes accident integrated dose.
APPENDIX C, Page C-2
Y 9a APPENDIX D BALANCE OF PLANT CRITERIA FOR EFIC This Appendix provides data for use in planning for installation of the Emergency Feedwater Initiation and Control System (EFIC). The data is of a general nature with exact values, counts, etc provided in the EFIC data. Since the data addresses no specific plant, the '
user must utilize the data and adapt it to this plant and mode of construction.
1.0 PHYSICAL SEPARATION The EFIC design provides for physical separation of redundant elements to promote single failure tolerance.
The user must extend physical separation outside the
' EFIC cabinets to preclude compromising single failure tolerance. Figures 1,2,3, and 4 depict the boundaries of separation of channels A, B, C, and D respectively.
Outside the EFIC cabinets the installer must ensure that:
i 1.1 All class 1E wiring and signals attendant to a 4
particular channel is maintained separate from like signals and wiring associated with the other channels.
1.2 All sensors providing input parameters to a particular EFIC channel are diversely located and/or protected with respect to like sensors for other channels to the extent that a given event (e.g., pipe whip, jet '
impingement, missiles, etc) and its effects cannot impair the operation of more than one channel.
1.3 Reference 1.1 above - all class 1E wiring and signals are maintained separate from non-lE circuits and wiring.
1.4 A given EFIC channel is assigned to the same division of plant separation as the NI/RPS and ESFAS channels which provides that EFIC channel's inputs.
1.5 EFW devices actuated by EFIC channel A are class lE train A devices located in the A division of plant separation. An exception is where the user provides qualified electrical isolation and separation between the class lE EFIC signal lines and the actuated device.
1.6 EFW devices actuated by EFIC channel B are class 1E APPENDIX D, Page 1 I
1 APPENDIX D cont.
train B devices located in the B division of plant separation. An exception is where the user provides qualified electrical isolation between the class lE EFIC signal lines and the actuated device.
1.7 All peripheral devices (e.g., remote switches, hand / auto stations, transmitters, indicators, etc) are:
1.7.1 Qualified as Class lE devices 1.7.2 Maintained in the same division of plant separation as the EFIC channel to which they are connected.
1.7.3 Physically separated and/or provided with barriers to separate them from Class lE equipment and wiring assigned to other divisions of separation.
1.7.4 Physically separated and/or provided with barriers to i
separate them from non Class 1E equipment and wiring.
j 2.0 ELECTRICAL ISOLATION NON 1E The EFIC is provided with electrical isolation devices which allow coupling of signals which originate in Class lE EFIC circuits to equipment in the non lE environment. These electrical isolators provide for decoupling the effects of fault potentials of 750V peak AC 60 HZ or 480 VDC in the non 1E environment from the EFIC proper. Typically these isolated signals are provided to the plant annunciator and plant computer.
The installer must ensure that:
2.1 Only electrically isolated signals are wired out of the EFIC to non lE devices and equipment.
2.2 Non IE wiring is routed so that faulting to potentials in excess of those indicated in 2.0 above is not I
credible.
2.3 Non IE wiring is maintained separate from Class lE wiring - Section 1.3.
3.0 GROUNDING Each EFIC channel will be provided with two ground terminals 1) safety and 2) instrument. The safety ground will provide for ground connection to the EFIC cabinet and structure. The instrument ground is electrically floating (not wired to cabinet ground).
APPENDIX D, Page 2
APPENDIX D cent.
It is recognirid that the user has provided grounding systems in h3.3 plant and has standard methods and philosophies which he employs. We recommend observance of the following rules to minimize potential ground problems.
3.1 Avoid Formation of Ground Loocs Each EFIC channel is designed to be an " electrical island." Where signals are coupled between EFIC channels, it is not necessary to interconnect instrument commons. Formation of ground loops cau .a part be avoided by:
3.1.1 Ensuring that all sensors float (are not ground referenced).
3.1.2 Where shielded cable is employed, ensure that it is grounded at only one and and has outer insulation sufficient to assure that it will not be inadvertently grounded anywhere along its length.
3.1.3 Ensure that all peripheral devices float (are not ground referenced.)
3.2 safety Ground l The safety grounds must be grounded in a manner that
- will ensure that, in the presence of hot shorts to the
( elevated to a potential, relative to surrounding structures, which represents a personnel safety hazard.
3.3 Instrument Ground Each EFIC channel (A,B,C, and D) is provided with an instrument ground point. The instrument ground for each channel should be:
3.3.1 Individually wired to the station ground.
3.3.2 Wired to the station ground with insulated cable to ensure that no inadvertent grounds occur along its length.
3.3.3 Provided with a removable link or other means of isolating the instrument ground from station ground for periodic tests to ascertain the EFIC channel has not developed inadvertent grounds.
APPENDIX D, Page 3
APPENDIX D cont. i l
1 4.O ELECTRICAL POWER REQUIREMENTS l Actual electrical power data such as consumption, inrush, etc will be provided as a part of the EFIC
' documentation. For planning and design purposes, the following requirements have been imposed on the EFIC vendor.
Primary Voltage: 120VAC 54 Primary Frequency: 60 Hz 2%
Maximum Current Consumption 20 amperes per Channel l
The EFIC must be powered by vital power sources. Each channel must be powered by the same vital power source as the NI/RPS and ESFAS channels which provide input signals.
5.O ELECTRICAL CURRENT RATINGS EFIC vector and trip busses transmit actuation signals into the field by applying vital input power to transmission lines. A trip bus can be loaded to a maximum of five amperes. A vector bus can be loaded to a maximum of two amperes.
It should be noted that a given channel A or B issues signals on ten trip busses (two for each of the five functions). For this reason - reference section 4.0 -
the total of trip bus loads, vector bus loads and cabinet instrumentation loads cannot exceed twenty amperes, of the twenty ampere rating - section 4.0 six amperes are reserved for instrumentation.
6.O CABLE COUNT This section provides estimates of the cable counts involved. Estimates are on the maximum side.
6.1 Vital Power By user - typically three conductors per channel APPENDIX D, Page 4 i
APPENDIX D cent, l
l 6.2 Level Sensors i There are presently two level sensors per channel per !
steam generator. Total of eight conductors per channel 1 exclusive of safety grounds, etc.
6.3 Pressure Sensors There is presently one pressure sensor per steam generator per channel. Total of four conductors per channel exclusive of safety grounds, etc.
6.4 ESFAS ECCS Actuation Presently there e.r3 two actuation signals from ESFAS actuation channel. Total of four conductors. This same format is repeated for channel B 6.5 NT/RPS Sicnals The following applies to the interface of each EFIC channel with the corresponding NI/RPS channel.
Sienal Conductors RC Pump 1A Trip 2 RC Pump 2A Trip 2 i RC Pump 1B Trip 2 l RC Pump 2B Trip 2 Sienal Conductors MFW Pump A & B Trip and 2 NI/RPS Channel Bypass 2 6.6 Plant Annunciator Sicnals Presently the following number of signals are available to the plant annunciator from each EFIC channel. To what extent they are utilized is the users option.
Each signal involves two conductors.
APPENDIX D, Page 5
APPENDIX D cont.
Channel No. of Sicnals A 28 B 28 C 8 D 8 6.7 Plant Commutet Each analog variable in each channel is available to the plant computer. Each signal is transmitted on one pair of conductors. Each signal pair should be shielded with the shield grounded at the computer. The input to the computer should float to avoid creating ground loops. There are six analog signals per EFIC channel.
6.8 Trin Busses Channel A and B sach originate ten trip busses for tripping actuated devices. Each trip bus is composed of two conductors.
6.9 Test Results Sianals The user provides one test results signal per each actuated device. Each signal is transmitted by a conductor pair. The user will determine the number of actuated devices.
6.10 Vector Sianals Each EFIC channel originates an open and close signal to SG A EFW valves as well as an open and close signal to SG B EFW valves. Total of eight conductors per EFIC channel.
6.11 EFW Control Valve Sianals Channel A provides one control signal for SG A EFW control valves. Channel A also provides one control signal for SG B EFW control valves. Each signal involves two conductors. The total is four conductors for channel A. This format is repeated for channel 3.
APPENDIX D, Page 6
APPENDIX D cont.
6.12 ADV Control Sicnals Channel A utilizes two conductors to transmit control signals to the SG A ADV. Channel B also utilizes two conductors to transmit control signals to the SG B AD7.
6.13 Main Control Room Refer to Figure 1 and 2. Channels A and B have an involved interface with the main control room. The following is a maximum estimate per channel.
Function Conductors
- 1) Trip, Reset, Manual Switches and 80 Backlighting
- 2) Post Accident Monitoring 12
- 3) Hand Control SG A Level 6
- 4) Hand Control SG B Level 6
- 5) Hand Control SG ADV 6
- 6) Set Point Selection 8
- 7) Auto /ECC SG A Selection 4
- 8) Auto /ECC SG B Selection 4 i
l APPENDIX D, Page 7
, . o l
j r
'f l
LEVEL ' " NI/RPS-A SOLID LINES-A DIVISION OF SENSORS -- -
SEPARATION CLASS lE
- PRESSURE SENSORS , =======
CLASS NON lE ESFAS ECC l r ACTUATION l VITAL CHANNEL A PRI.PWR.
U U Co SGA EFW r- 7 r- 7 r- 7
!." CONTROL -
l l l l l l S VALVE
]
x SGB E N EFIC A lEFIC Bl IEFIC CI lEFIC DI j . CONTROL -
l l l l l l
) u VALVE
- 1 I I
- I I l j SGA ADV +
g__g g__g L__g o il d u n
! PLANT s l
ANNUNCIATOR " t ; Im% ,
RANT M TRAIN A EFW i
COMPUTER 4 DEVICE CONTROL
- CENTER (TRIPS)
SGA EFW VALVES TRAIN A EFW (VECTOR SIGNALS) W '
DEVICE TEST RESULTS
, SGB EFW VALVES l (VECTOR SIGNALS)
MAIN CONTROL ROOM REMOTE TRIP SWITCH COMPLEX, FIGURE I l' EFIC CHANNEL A HAND CONTPOL-SGA e. SGB
' = LEVEL-SGA ADV, AUTO SEPARATION
! SELECTION-SGA AUTO /ECC SGB AUTO /ECC, POST ACCIDENT j
MONITORING _ . _ . . . . _ _ _ . .
e o i
LEVEL , r NI/RPS-B SENSORS -
PRESSURE SENSORS ,
SOLID LINES-B DIVISION OF r ACTUATION SEPARATION CLASS lE VITAL CHANNEL B
- ======
CLASS NON IE INTEHCHAt4EL
- r v , 7 ll If If ll l I c- , r- , r- ,
-l l l l l l 1 lEFIC A! EFIC B IEFIC Cl IEFIC D!
I I I I I I SGA EFW CONTROL VALVE m I I I l ! !
L__J L__J L__J i 3GB EFW Hh CONTROL ) J VALVE
! PLANT SGB ADV M s l ANNUNCIATOR 2 PLANT J TRAIN 8 EFW j % COMPUTER W OEVICE CONTROL
{
CENTER (TRIPS)
SGA EFW VALVES TRAIN 8 EFW (VECTOR SIGNALS) W ' DEVICE TEST RESULTS fkC N N $ bS) W - - - - - - - - - - - - - - - - -
MAIN CONTROL ROOM FIGURE 2 EFIC CHANNEL B a.
REMOTE TRIP SWITCH COMPLEX, SEPARATION
' HAND CONTROL-SGA & SGB
= LEVEL-SGB AOV, AUTO SELECTION-SGA AUTO /ECC ',
g5GO AUTO /ECC, POST ACCIDENT -'
LMONITORING _ _
o,y o l ' , NI/RPS-C ORS r PRESSURE SOLID LINES-C DIVISION OF SEPARATION CLASS lE
- - = = = = -
, CLASS NON lE
" F r- 7 r- 7 r- 7 l l l l l l l v IEFIC Al IEFIC Bl EFIC C IEFIC D!
's l I I I I I
? I I I I I i l 5 t__.; t__J L__J a o n
( t A ;
INTERCHANNEL PLANT w " SGA EFW VALVES COMPUTER (VECTOR SIGNALS) yygggg 3 PLANT d SGB EFW VALVES EFIC CHANNEL C ANNUNCIATOR (VECTOR SIGNALS) SEPARATION
&y
)
ORS ' # "I ~O PRESSURE SENSORS ,
3 VITAL '
m u
S* r- 7 r- 7 r- 7 ". U - SOLIO LINES-D DIVISION OF SEPARATION CLASS lE
_o l I I I I I 80 IEFIC Al IEFIC BI IEFIC Cl EFIC O - =^=
CLASS NON IE I I I I I I O
1 6 I I I I I I L__J L__J L__J _. . . . _
I l il i l i L L t J INTERCHANNEL PLANT w SG Eh'W VAL 5ES COMPUTER (VECTOR SIGNALS)
_ _ _ _ _ . . . . . . _ . . . . _ . . . _ - FIGURE 4 PLANT. W " SGB EFW VALVES EFIC CHANNEL D ANNUNCIATOR (VECTOR SIGNALS) SEPARATION i
I